[petsc-users] Questions about MatConvert BAIJ to AIJ

[Barry Smith]

> On Mar 18, 2015, at 3:07 PM, Chung-Kan Huang <ckhuangf at gmail.com> wrote:
> 
> So I guess I misunderstood the meaning of " inplace conversion".
> and what do MAT_INITIAL_MATRIX and MAT_REUSE_MATRIX do anyway?

  No you have not misunderstood it.

Currently
   MAT_REUSE_MATRIX is only supported for inplace conversion, otherwise use
   MAT_INITIAL_MATRIX.

  For testing purposes you can use MAT_INITIAL_MATRIX. 


> 
> 
> 
> 
> On Wed, Mar 18, 2015 at 2:48 PM, Jed Brown <jed at jedbrown.org> wrote:
> Chung-Kan Huang <ckhuangf at gmail.com> writes:
> 
> > Yes, I was suprised that I can still use MatSetValuesBlocked after I did
> > MatConvert MATBAIJ to MATAIJ.
> >
> > Then I just found the mat type is still seqbaij which means the MatConvert
> > didn't work.
> >
> > This is how I did MatConvert
> >
> > MatConvert(J, MATAIJ, MAT_REUSE_MATRIX, & J);
> >
> > where J is my Jacobian matrix.
> 
> Seems to me this should fail because you didn't MatConvert this matrix
> yet.  Anyway, you should use MAT_INITIAL_MATRIX and put the result in a
> new Mat.
> 
> 
> 
> -- 
> Cheers
>